Polarity???

Question

Water is a polar solvent whereas TTE is not very polar. How does polarity influence the solubility of potassium iodide, camphor, zinc, and silicon dioxide?

TTE is trichlorotrifluoroethane

Answer 1

When thinking about solvents there are two things to remember. "Like Dissolves Like" and "Opposites Attract"

Water is a v-shaped molecule which positively charged at the end with the two hydrogen atoms, the other end with the oxygen atom is negatively charged. It has a positive pole and a negative pole, that is why water is called a polar solvent. TTE is a linear molecule with negatively charged electrons shared among the carbon atoms and the chlorine and fluorine atoms. TTE is nonpolar because it has no one end which has a particular charge.

Potassium chloride is a salt. It has a negatively charged chlorine atom and a positively charged potassium atom held together by attraction of opposite charges. Hence it has one end which is positive, and one which is negative (like dissolves like.) It dissolves readily in water because the ions are attracted to the ends of the water molecule with the opposite charge (opposites attract.)

Camphor is a somewhat larger molecule than TTE or water. Like TTE, negative charges (electrons) are distributed evenly around the molecule. Since there is no one end which has a positive or negative charge, camphor is a nonpolar molecule. It will not dissolve in water to any great extent since there are no distinct areas of positive and negative charge (opposites attract.) Camphor will dissolve in TTE because the chlorine and fluorine atoms will also attempt to share electrons with the carbon atoms in camphor (like dissolves like.)

Zinc ( I assume zinc metal powder or granules) will not dissove in either solvent to any extent. Zinc metal is composed of atoms closely bonded together in a crystal structure, much like bricks in a wall. There is no sharing of electrons between the zinc atoms, therefore a nonpolar solvent will not dissolve zinc. There is no positive or negative end in a single atom, therefore water will not dissolve zinc either.

Silicon dioxide (SiO2) is the chemical formula of sand. Almost nothing will dissolve silicon dioxide with the exception of some really dangerous acids. Silicon dioxide is a linear molecule containing a silicon atom and two oxygen atoms. In SiO2, the silicon atom shares electrons with the two oxygen atoms. It is nonpolar because there is no one end of the molecule that has a specific charge (unlike solvent.) TTE will not dissolve SiO2 because the oxygen atoms share two electrons with the silicon rather than one like the chlorine and fluorine. The bonds between oxygen and silicon are much stronger than those between carbon and chlorine or fluorine. The electrons are more closely held and evenly distributed around the SiO2 molecule. The electrons are less prone to being shared by the chlorine and fluorine atoms in TTE.

Answer 2

What is TTE? ok, triflouroethane or TFE

In any case, based on your info, use the principle of "like dissolves like".

Water, a polar molecule with dissolve those that are ionic and polar also like KI.

TTE or TFE, not very polar will dissolve camphor.

Both Zinc, in the form of metal and silicon dioxide( think of pure sand grains) will not be soluble in water or TFE.